Horizontal powder press



July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 7 Sheets-Sheet 1 2 'PI LEFTRIGHT PUNCH 45% DROP PUNCH ANoDE' PRESSURE SIMULTANEOUS PREss|NG ANODELENGTH p ofq I 2 L '3 LEFT f RIGHT PUNCH 63% DROP PUNCH \UNIFORM Q ANODEI W PREssURE ISIMULTANEOUS PRESSING I P P I ANODE LENGTH P NET EFFECT, PANC 2' PRESSING P L 1 LEFT2 0 RIGHT PUNCH E PUNCH UNIFORM 2ND\ \ISTPRESSING PRESSING .k SEQUENTIAL PRESSING z i of/NVE/WDRS 6 ea v/- e.%gANGDE LENGTH 3p0 d2bZ6i5M-% dm(%ww=' ATTORNEYS July 11, 1967 c. E. LEROY ETAL 3,330,000

HORIZONTAL POWDER PRESS 7 Sneets-Sheet 2 Filed June 18, 1965 .4rromvsgg.

July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 '7 Sneets-Sneet 3 l MATCHLIN E A TTORNEYS July 11, 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Filed June 18, 1965 7 Sneets-Sheec 4 I M ATC HMATCH A r TORNEYS July 11, 1967 c. E. LE ROY ET AL 3,330,000

' HORIZONTAL POWDER PRESS Filed June 18, 1965 '7 Sheets-Sheet 5 MATCH INVEN TORS azz ame-CZ G. Zak/-24 Z Waczmzl "p wg wdai n Z 1 July 11, 1967c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS Fild June 18, 1965 7 Sheets-Sheet 6 635.25%erzeda MIMI f A TTOR/VEYS ly 1}], 1967 c. E. LE ROY ETAL 3,330,000

HORIZONTAL POWDER PRESS 7 Sheets-Sheet '7 Filed June 18, 1965 ATTORNEYSdab? wk v3 1 v Crea$ i g7 59 M J42 flbacewm f -bkk fi United StatesPatent 3,330,000 HORIZONTAL POWDER PRESS Chester E. Le Roy, Waukegan,11]., Benedict G. Barth,

Kenosha, Wis., and Edwin L. Macrowski, North Chicago, and Earl K.Takata, Arlington Heights, 111., assignors to Fansteel MetallurgicalCorporation, a corporation of New York Filed June 18, 1965, Ser. No.465,093 7 Claims. (Cl. 1816.5)

This invention relates to apparatus for fabricating pressed powderproducts and more particularly to a horizontal press for fabricatingpressed powder electrodes of uniform density.

In post World War II years, an entirely new technology has emerged basedon metals having extremely high melting point temperatures, therefractory metals. Because of their unique characteristics, theimportance of these metals and the variety of uses to which they havebeen put has increased dramatically. However, inherent in their newfoundutility are problems which create difliculties not encountered in themetallurgy of more familiar metals.

One major problem arises from the high melting point of such refractorymetals including, for example, tungsten, tantalum, molybdenum,columbium, and others. Thus, many products which might otherwise be madeby the usual metallurgical processes of melting, forging, casting, etc.,have been developed by a nonanalogous technologypowder metallurgy. Theseproducts which have been produced from powder must often meet highstandards not only of purity of the metal itself, but in consistency oftheir characteristics and in their performances. One such typicalproduct is the tantalum capacitor in which the anode or positiveterminal of the capacitor is made from tantalum powder. These anodes andsimilar devices are formed by pressing the tantalum powder under a highpressure and then sintering the powder so that the individual particleswill form a bond with each other.

The use of such tantalum capacitors has increased because of tantalumshigh performance over wide ranges of tempeartures to which thesecapacitors are subjected. Thus, capacitors with tantalum electrodes areoften utilized in space and other highly sensitive areas in which thecharacteristics of the components cannot vary one from the other, norunder the varying atmospheric and environmnetal characteristics to whichthey are subjected.

One of the major problems in the production of such products is that thevariations in the density of the pressed anode cause variations in theelectrical characteristics of the capacitors in which they are utilized.In fact, lack of uniformity in density of these anodes, if notcontrolled, may result in a substantial rejection rate of the capacitorsbecause of their inability to perform up to the high standards requiredof them.

While, for the sake of simplicity, the following description in regardto the present invention will be directed toward an apparatus for theproduction of pressed tantalum electrodes, it should be understood thatthe apparatus embodying the present invention may be utilized to compactor press other powder to produce other desired products.

Although theoretically desirable, practically it is not possible toproduce pressed powder electrodes which have absolute uniform densitythroughout their entire length and thickness. Any increase, however, inthe uniformity of the density of pressed powder electrodes is, ofcourse, valuable and does result in a substantially improved electrode.

Existing devices, in which powder is pressed along a generally verticalaxis, have certain characteristics which inherently reduce theuniformity of electrode density. Thus, in such devices, the powder, byits own weight,

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presses against the lower end of the die, thereby causing increaseddensity at one end of the electrode. In the production of electrodes,powder is often pressed around a wire which is used as a lead orelectrical connection thereto. In existing devices, in which a wire isinserted from above the powder into the powder fill, the wire acts tocompress or precompact the powder fill in its path as it is inserted. Inthose devices in which the wire extends up from the bottom of the diecavity, the powder tends to pass around the wire into the wire feedaperture which makes it difiicult to allow for a continuous feed ofwire.

In accordance with the present invention, however, there is provided adevice which is capable of increasing the uniformity of the density ofpressed metallic powder electrodes. This device differs from existingapparatus primarily in that it operates along a substantially horizontalplane and, furthermore, provides pressing in synchronized and successivesteps.

Pressing along a horizontal plane allows for increased unifonnity in theproduct since, in contrast to vertical pressing, the powder, by its ownweight, does not tend to compact towards one end of the electrode.Furthermore, a horizontal oriented device may provide a chamber in whichloose powder can be positioned completely around the wire prior topressing without prepressing the powder. The horizontal orientation alsofacilitates continuous wire feed, selection and control of anode leadlength and automatic operation of the press.

By'the present invention, modification in the pressing operation,facilitated by the horizontal orientation of the press, further providesfor increased uniformity in the density of the pressed powderelectrodes. This modification contemplates sequential pressing fromeither end of the pressing cavity. Under existing procedures of pressingthe powder from one end against a stationary backup member, the densityof the compact varies as a function of the electrode length and issubstantially less at the end adjacent the stationary member than at theend adjacent the pressing member. Pressing simultaneously at both endsdoes not correct this deficiency but merely creates, in effect, twoshorter electrodes having a stationary point of minimum densitysomewhere between the electrode.

ends.

This phenomenon results from normal frictional forces within thepressing cavity. Thus, as a result of pressure applied to one end onlyof powder, the powder is initially compacted and grain are moved towardthe stationary member from the end of the pressing member. However, thewalls of the cavity cause a certain amount of frictional drag,therefore, the force applied to any segment of 'the powder decreases asdistance from the pressing element increases. Thus, when pressing onlyfrom one end, the powder at the opposite end is not moved at all and hasa minimal amount of pressure applied to it. At that point, therefore,the electrode is least dense.

In simultaneous pressing from both ends a similar phenomenon occurs, thedifference being only that the stationary plane or unmoved powder islocated somewhere between the ends of the powder. Thus, at a givenpoint, depending upon the relative pressures applied to either end ofthe powder, a fixed plane could be inserted into the powder withoutdisturbing the pressing forces from either end. At this point, thedensity of the electrode is lowest, and if the distance from this pointto the end of the electrode were the same as .the total length of anelectrode being pressed from only one end, both electrodes would havesubstantially the same density characteristics.

However, if all the powder could be shifted in one direction or theother, the density of the overall electrode at any given point would begreater than the density of an electrode formed by either the one-endedor two-ended simultaneous pressing methods. The horizontal pressincorporating the features of the present invention pro- 7 vides such astaggered pressing operation.

end of the electrode, thereby increasing the overall uniformity of thepressed electrode.

More specifically, the present invention incorporates a horizontal borehaving a pressing cavity at one end. A selected amount of powder is fedinto the bore normally at a point adjacent to and aligned with thepressing cavity.

Pressing of the powder within the pressing cavity is accomplished by twopressing members, one located in the bore on one side of the cavity andthe other located on the other side of the cavity. When the powder is tobe pressed around a wire, the wire may conveniently be led into thecavity through one of the pressing members.

After the powder has been dispensed, one pressing member moves forwardagainst the powder forcing it into the pressing cavity. Meanwhile theother member has moved into the cavity and is fixed there to act as abackup punch. The pressing member moves in against the powder for agiven distance to compress the powder to a selected 'size and density.When this pressing has been completed and the pressing member isstopped, the backup punch is then jogged forward against the powder apreselected amount, which increasesthe overall density of'the electrodeand improves the uniformity of the density across the entire length ofthe product.

The control of the backup member is synchronized to the action of thepressing member. The backup member may be supported externally of thebore in a support mounted in a pressure applying means. When the backupmember is initially moved into the pressing cavity, pressure iscontinuously applied thereto even though it is prevented from movementinto the cavity while the pressing member initially presses the powder.Conveniently, the backup member may then be moved into the cavity byreleasing it from its first fixed position. allowing it to move forwardunder the sustained pressure applied thereto until it is again stoppedat a predetermined point.

Once the aforementioned pressing action has been completed, the backupmember is retracted from the cavity and the pressing member is thenmoved forward to eject the pressed electrode from within the cavity. Ifthe electrode has been pressed around a wire, the wire may be drivenfurther independently of the pressing member for a preselected leadlength and severed to completely discharge the pressed electrode fromthe apparatus.

Thus, the present invention is capable ofproducing an improved pressedpowder electrode or similar product having a more uniform density acrossits entire length than a previously possible. In accordance with theinvention, this increased uniformity is provided by staggered pressingof the powder and, furthermore, such staggered pressing is more easilycontrolled and the general consistency of the product is increased bypressing the product along a horizontal plane. 7

Numerous other advantages and features of the pres ent invention willbecome readily apparent from the following detailed description of theinvention and one embodiment thereof, from the claims, and from theaccompanying drawings in which each and every detail shown is fully andcompletely disclosed as a part of this specification, in which likereference numerals refer to like parts, and in which: 7

FIGURES 1a, 1b, and 1c are plots of electrode pressure versus electrodelength for various pressing actions;

FIGURE 2 shows the arrangement of FIGURES 3a, 3b, 3c, and 3d;

FIGURES 3a, 3b 3c, and 3d are, when arranged in accordance with FIGURE2, a diagrammatic elevational V pressed is supplied to a powder fillchamber 18 adjacent view partially in section of the horizontal pressincorporating features of the present invention;

FIGURE 4 is a vertical sectional view showing the powder dispenser andreservoir taken along the lines 44 of FIGURES 3c and 5; V

FIGURE 5 is a side sectional view of the dispenser taken along lines 55of FIGURE 4;

FIGURE 6 is a plan view of the backup punch and its control mechanismpartially broken away showing,

the portions disposed below the mechanism; and

FIGURE 7' is another plan view showing additional pressed simultaneouslyby unequal forces. FIGURE 10.

shows how the uniforfmity of electrode density is substan tiallyincreased by staggered synchronized pressings In the disclosedembodiment, pressed electrodes are formed by pressing powder within acavity 10 defined by a replaceable carbidedie 12 between two punches, abackup punch 14 and a pressing punch 16. The powder to be to thepressing cavity 10 by a powder dispensing mechanism 20 disposed abovethe chamber. v Referring to FIGURES 4 and 5, there is shown a reser-'voir 22 disposed above the powder dispensing mechanism 20 which, inturn, is located above the filling chamber 18. The reservoir 22 is heldin place bya bracket 24 which is mounted to the main powder dispensinghousing 26. The powder reservoir 22 terminates at the upper end of atapered aperture 28, the lower end of which com- 42 throughapproximately wherein the powder in' the compartment 30 is dumpedinto apowder trough 44 leading to the top of the powder fill chamber 18.

V The top of the powder fill chamber is defined by areciprocallyslidable wedge 46 fastened to the lower end .of a wedgesupport piece 48. A slot 50 in wedge support piece 48 engages aneccentric 52 mounted on one end of a shaft 54 which is rotated by thedispensing rack 40 through pinion 55 while dispensing the powder. Thus,the powder fill chamber 18 is open to the trough 44 as the powder isbeing dumped into the trough and is closed as the powder dispensingcompartment .30 is returned to its powder receiving position in thereservoir 22.

While one particular dispensing mechanism has been described, it isclear that any suitable mechanism'may be used with the press.incorporating the present invention, such as that disclosed by J. D.Winters et al., in Patent No. 2,820,577, entitled Powder Feed Mechanism.The only requirement is that thepowder dispensing me'cha nism be capableof supplying a preselected amount of powder at the proper time to thepowder fill chamber 18.

.Referring to FIGURES 3a, 3b, 3c, and 3d, the pressing a V punch 16 iscarried by a punch holder 56 supported 7 throughout the entire cycle ofoperation in a bushing communication with V 56, and pressing punch 16 incase the machine jams or when the pressing punch is to be removed, i.e.,when the size of the punch is changed for production of various sizeelectrodes.

A wire 70 about which the powder is pressed feeds into the cavity arounda wire tensioning device 72, through a wire feed clamp 74 and electrodeejection clamp 66, a horizontal bore 76 formed in the punch holderextension 62, punch holder 56, and the punch itself. The wire tensioningdevice 72 includes a tension disc 78 around which the wire is wound andwhich is attached to a shaft 80 rotatably supported in a bushing 82slidably mounted on a straightener support plate 84 which is fixed tothe main frame 60. The shaft 80 and bushing 82 slide within a guideplate 86 and tension on the disc 78 is maintained by a spring 88connected between the slidable bushing 82 and the end of the supportplate 84.

The housing 89 of the wire feed clamp 74 is afiixed to a feed clampslide block 90 which is bolted by suitable bolts 92 to a yoke 94, theother end of which is connected to one end of a spring biased rod 96.The wire 70 is kept under constant tension to insure a more uniform wirelead length by a spring 98 acting between the end of the main frame 60and a washer 100 fixed to the outer end of the rod 96 to bias a camfollower 102, bolted to the bottom of the wire feed clamp slide 90against the surface of a wire feed cam 104 keyed to the main drive shaft106 of the press. The main shaft 106 is supported by pillow block 107fixed to the frame 60. One end of the slide block 90 is fitted with ahardened stop 108 which is designed to contact the end of an adjustablestop screw 110 to limit retraction of the feed clamp 74 and therebycontrol the lead length inside of the anode.

The wire feed clamp housing 89 is provided at either side with apertures112 through which the wire 70 passes from the wire tensioning device 72to the cavity 10. A fixed wire clamping jaw 114 is disposed within thehousing 89 and below the level of Wire housing apertures 112. A dowelpin 116 connects a movable jaw 118 disposed above the apertures to apiston 120 which is raised and lowered by a compressed air cylinder 122supported above the housing by a bracket 124 and clamp 126. The cylinder122 is selectively actuated in any suitable manner, such as by a limitswitch 128 energized by a limit switch cam 130 fixed to the main driveshaft 106.

Another clamping assembly, the electrode ejection clamp 66, is disposedbetween the wire feed clamp 74 and the powder dispensing mechanism 20.This clamp, of a similar structure to the wire feed clamp, is alsoprovided with apertures 132 in its housing 64 through which the wire 70passes. A wire support tube 134 which prevents buckling of the wireextends through one of the apertures 132 in the housing 64 of theelectrode ejection clamp 66. Similarly to the wire feed clamp 74, theelectrode ejection clamp 66 is provided with a lower fixed clamping jaw136 and an upper movable jaw 138 reciprocated by a piston 139 attachedthereto through a dowel pin 140. The piston 139 is driven by an aircylinder 142 supported on top of the housing 64 by a suitable bracket144 and clamp 146.

, The, electrode ejection clamp housing 64 is bolted to a slide block148 to which a cam follower 150 is attached by a suitable nut and boltassembly 152. The cam follower 150 rides in the track of the electrodeejection cam 154 keyed to the main drive shaft 106 which causesreciprocal movement of the clamp 66. As explained above, the pressingpunch 16, punch holder 56 and punch holder extension 62 are mounted onone side of the electrode ejection clamp housing 64. The cylinder 142 ofthe electrode ejection clamp is selectively actuated by a limit switch156 which is suitably energized, e.g., by another cam 158 similar to thewire feed clamp switch energizing cam 130.

As indicated above, the apparatus is provided with a second pressingmember, the backup punch 14 which is mounted in a backup punch support160 that is supported as it reciprocates to and from the cavity 10 in afixed bearing block 162. The backup punch support 160 is attached to thepiston 164 of a compressed air backup punch control cylinder 166attached to a backup slide 168 by suitable fastening bolts 170. A camfollower 172 is attached to the backup slide 168 by a suitable nut andbolt assembly 174 and rides in the track of a backup cam 176 keyed tothe main drive shaft 106.

Referring now also to FIGURES 6 and 7, there is shown threaded to thebackup punch piston an adjustable stop ring 178 which is designed toengage a stop lever 180 attached to a stop lever mounting plate 182disposed below the piston 164. As the air cylinder 166 continues to moveforward toward the cavity 10 under control of the backup punch cam 176,it carries the piston 164, support 160 and punch 14 forward until thering 178 engages the stop lever 180. The cylinder 166 continues forward,and applies pressure to the piston 164 to fix the backup punch 14, whichat this point is located within the pressing cavity 10, in place withthe ring 178 hard against the lever 180. As the cylinder 166 continuesto move forward, an actuating rod 184 mounted on the cylinder 166engages a stop lever release latch 186 to release the stop lever 180 andallow the piston 164 to move forward under air pressure until the stopring 178 engages a fixed stop 188 located below the stop lever 180.

Retraction of the backup piston 164, backup punch support 160 and backuppunch 14 is provided by mechanically connecting the piston 164 to thecylinder 166. A catch rod 1919, supported on the adjustable stop ring178, extends back parallel to and above the latch release actuating rod184 and through a retracting catch supporting member 192 mounted on thecylinder 166. A spring loaded retracting catch 194 slides along theouter diameter of the catch rod and over a catch ring 196 fixed to theextremity thereof as the cylinder 166 moves forward as previouslydescribed. At the point where the actuating rod 184 releases the stoprelease lever 180, the spring loaded retracting catch 194 engages thecatch ring 196 so that when the backup cam 176 causes the cylinder 166to retract, the piston 164 is mechanically coupled thereto as shown inFIGURE 6 and is immediately retracted therewith. As the cylinder 166returns to its completely retracted position, a release screw 198 inline with the extension on the retracting catch 194 engages it torelease the catch ring 196, thereby allowing for repetition of thecycle.

In operation, at about the time a cycle is completed, the electrodeejection punch cam 154 starts retracting the electrode ejection clamp 66and the pressing punch 16 attached thereto. At about this time, thepowder dispensing mechanism 20 operates as previously described todispense powder into the powder receiving chamber 18 simultaneouslylifting the chamber cover or wedge 46 so that the powder falls into thechamber. When the clamp 66 has positioned the pressing punch 16immediately adjacent the chamber 18, the associated switch cam 158de-energizes the ejection clamp 66 releasing the wire 70 just after thewire feed clamp cam 130 activates its limit switch 128 to cause the feedclamp 74 to grip the wire 70. The wire feed clamp 74 then retracts underpressure of the biasing spring 98 until the hardened stop 108 located inthe wire feed clamp slide block 98 engages the adjustable anode leadlength screw 110.

At this point, the electrode ejection clamp 66 is reenergized clampingthe wire 70 and the wire feed clamp 74 releases the wire. Simultaneouslywith this action, the backup feed cam 176 advances the cylinder 166 andpiston 164 until the adjustable stop ring 178 engages the stop lever18!) at which point the leading edge of the backup punch 14 is disposedwithin the pressing cavity 10. The cam 176 continues to advance thecylinder 166,

thereby keeping pressure on the piston 164 and the backup punch support160, so that the punch 14 remains absolutely stationary within thecavity 10. By this time, the powder dispensing operation is completedand the power fill chamber covering wedge 46 has returned to cover andcompletely enclose the powder fill chamber 18.

The pressing operation is now commenced by advancing the pressing punch'16 and wire 70 through the chamber 18 and into the pressing cavitypushing the powder in front of it. This is accomplished by the electrodeejection cam 154 advancing the associated. clamp '66 which, because itis energized, maintains the wire 70 fixed relative to the punch 16. Thisaction continues for a predetermined distance until the pressing strokeis completed.

As'the electrode ejection cam 1'54 brings the clamp and punch to a halt,the air cylinder 166, which has advanced under control of the backuppunch cam 176, reaches the point where the actuating rod 184 engages thestop lever release latch 186 thereby disengaging the lever 180 fromengagement with the adjustable stop ring 1 78. Due to the high airpressure that has built up on the back of the piston 164, the backuppunch 14 is driven a short distance into the cavity 1% to provide thesecondary reverse pressing action until the stop ring 178 drives thestop lever 180 against the fixed stop 18S disposed below the lever.Immediately after this pressing stroke, the backup cam 176 retracts thecylinder 166 which, as explained above, having engaged the piston 164mechanically via the catch 194, catch ring 196 and rod 190, withdrawsthe backup punch 14 from within the pressing cavity 10. 7

When the backup punch 14 has been retracted, the electrode ejectionclamp cam 154 again advances the clamp 66 driving the pressed electrodeout of the cavity 10 until it is held only by the wire 70 over aconveyor belt 260 which carries the ejected electrodes away from theapparatus. The wire feed clamp 74 is now re-energized and the electrodeejection clamp 66 is de-energized. The wire feed clamp 74 is thenadvanced by the feed clamp cam 104 which, since it is clamped to thewire 70,

further ejects the electrode from the machine so a cutting 'mechanism(not shown) of anysuita'b-le type can be activated to cut the wire 70and disengage the electrode from the machine. The clamps 66, 74 are thenretracted as aforementioned and the cycle is repeated.

Thus, there has been shown and described a new and novel device forpressing products from metallic powder or any other similar substance.The press is capable of functioning automatically and continuouslyproviding a constant feedof wire so the electrode may be. pressedtherearound to form a lead integral therewith.

Furthermore, the disclosed press provides for increased uniformity ofthe compacted electrodes not only because of horizontal orientedpressing, but also because of its controlled, synchronized, staggeredpressing operation. This allows for not only a higher uniformity in thedensity of the'pressed electrodes as a function of length oftheelectrodes, but has provided for more'uniformity from product toproduct. 7

It will be readily observed from the fore-going detailed description ofthe invention and in the illustrated embodiment thereof that numerousvariations and modifications may be effected without departing from thetrue spirit and scope of the novel concepts and principles of thisinvention.

What is claimed is:

pressure to said second pressing member, means for retaining said secondpressing member stationary in one end of said die cavity while underpressure, means for advancing said first pressing member through saidchamber topress powder in said cavity against said stationary secondmember, means for releasing said second mem-.

ber retaining means upon completion of pressing by.

said first pressing member, said second member upon release of saidretaining means advancing in response to the pressure from said pressureapplying means to fur-' ther press the powder in said cavity againstsaid stationary first member, and means for ejecting the pressed product from the apparatus. a

2. A powder press for producing uniform pressed powder productscomprising in combination a die having.

a pressing cavity therein, a first punch disposed at one side of saidcavity, said first punch adapted to have a wire pass there-through andextend therefrom, a backup punch disposed in the opposite side of saidcavity, means 7 for advancing said first punch and wire into said cavityto press powder therein around said 'wire and against said backup punch,means synchronizedto cessation of.

nism for controlling movement of one'of said punches 7 comprising apunch support carried by an air cylinder;

means coupled to said cylinder for displacing said cylin der and saidsupport towards the pressing cavity, stop means engaging said supportfor interrupting movement of said support and'pu-nch while the otherpunch is being operated, means attached to saidv cylinder for releasingsaid support stop means to allow for pres-sing displacement of saidpunch into the cavity, and catchmechanis'm responsive to thedisplacement of said support for me.- chanically connecting saidsupportand cylinder.

4. A press for producing an electrode from metallic powder comprising incombination means defining a horizontally disposed'hollow bore providedwith a powder receiving chamber, means defining a pressing cavityadjacent to said chamber, a powder dispensing mecha-' nism disposedabove said chamber, said dispensing mechanism operable to open the topof said chamber and provide a measured supply thereto of powder forpressing, said powder dispensing means operable to close said chamberupon completion of said supplying operation, a

1. Apparatus for forming a product pressed from powder comprising incombination means defining a-ho-rizonta'lly oriented bore'including apowder chamber, a pressing die provided with a cavity adjacent to andaligned with said bore, a dispensing mechanism for supplying powder tosaid chamber, a first powder pressing member disposed in said bore onone side of said chamber, a second powder pressing member, 'means forapplying pressing punch disposed at one'end of said chamber oppositefrom said cavity, said pressing punch adapted to have a'wire passtherethrough and into said chamber, a backup punch mounted in one end ofa support and piston, a. compressed air cylinder coupled to said piston,means displacing said cylinder towards the :said cavity, a stop leverengaging the support when said backup punch has entered the cavity tointerrupt displacement thereof, a mechanism synchronized with thestopping of said backup punch for displacing said pressing punch throughsaid chamber and into said cavity to compress said powder, lever releasemeans on said cylinder synchronized with completion of said pressingpunch displacement for engaging said stop lever to release said support,said cylinder driving saidbackup punch under pressure against saidpartially compressed powder to complete compression thereof from the endopposite to that'pressed by said pressing punch, a catch connecting saidbackup punch with said cylinder upon completion of said backup pres-singto allow for positive withdrawal of said punch on retraction, of saidcylinder, and means displacing said 'wire to eject said pressed productfrom said cavity.

5. Apparatus for forming a compacted product from powder including incombination means defining a cavity in which the powder is pressed,dispensing means for supplying powder, a pair of powder pressingmembers,

means for advancing one of said members into said cavity to press powdertherein against the other of said members, and mechanism for controllingmovement of said other member comprising means for applying pressure tosaid other member to advance it into said cavity, means for interruptingthe advance of said other member while said one member is advancing intosaid cavity, fixed stop means, and means releasing said interruptingmeans when said one member has advanced into said cavity whereby saidpressure applying means causes said other member to spring into saidcavity to further press said powder until engaged by said fixed stopmeans.

6. A mechanism for controlling action of a powder pressing membercomprising a support afiixed to said member, means coupled to saidsupport for applying pressure thereto, means connected to said pressureapplying means for advancing said pressure means, support and pressingmember towards a powder pressing cavity, a stop lever engaging saidsupport to interrupt its movement towards the cavity, a stop leverrelease attached to said pressure applying means for releasing saidsupport stop lever as said pressure means is advanced, a fixed stop forlimiting amount of movement of said support and said member when saidstop lever is released, a catch for connecting said support to saidpressure applying means when said support contacts said fixed stop, andmeans for retracting said pressure means and said support and memberconnected thereto.

7. A horizontal press for production of pressed powder electrodesincluding in combination means defining a horizontally disposed boreprovided at one end with a powder receiving chamber, an interchangeabledie positioned at one end of said bore and defining a pressing cavityaligned with said chamber, a powder supply reseivoir disposed above saidchamber, powder dispensing mechanism for communication between saidreservoir and said chamber, said powder dispensing mechanism including arotatable metered compartment for measuring the amount of powder to bedispensed and for dumping the powder therein into a chute communicatingwith said chamber, a reciprocable wedge forming part of the wall of saidchamber, and means for alternately rotating said compartment and raisingsaid wedge whereby powder dumped into said chute falls into said chamberand for returning said dispenser and wedge to their original positionswhereby said compartment communicates with said reservoir and said wedgecloses said chamber, a powder pressing punch disposed in said boreadjacent to said chamber, said pressing punch adapted to have a Wirepass therethrough and into said chamber, a horizontally orientedcompressed air cylinder, a support piston carried by said cylinder, abackup punch supported in said support piston external to said die andaligned with said cylinder, means connected to said cylinder foradvancing it towards said cavity whereby said piston and backup punchare also advanced, a stop lever engaging said piston to interrupt itsmovement when said backup punch is in said cavity whereby continuedadvance of said cylinder increases the pressure on said piston, meanssynchronized to the interruption of said backup punch movement foradvancing said pressing punch and wire through said chamber and intosaid cavity to press the powder in said cavity around said wire andagainst said backup punch, a fixed stop, a stop lever release mounted onsaid cylinder and synchronized with completion of pressing punchmovement for releasing said stop lever whereby pressure on said pistoncauses said backup punch to spring into said cavity until said pistonengages said fixed stop, a retracting catch for mechanically connectingsaid piston to said cylinder when said piston has engaged said fixedstop, said cylinder advancing means synchronized to said fixed stopengaging said piston for retracting said cylinder whereby said backuppunch is withdrawn from said cavity, and means synchronized with removalof said backup punch for advancing said pressing punch and wire togetherand for subsequently advancing only said wire whereby said pressedpowder electrode is ejected from said cavity.

References Cited UNITED STATES PATENTS 1,638,002 8/1927 Lynn 18-36 XR2,384,163 9/1945 lFlowers 18-16.5 2,762,078 9/1956 Haller 18-16.52,777,162 1/1957 Banzhof 18-16.5 2,798,255 7/ 1957 Winters.

2,821,748 2/1958 Willi 18-16.7 3,149,375 9/1964 Gehl 18-36 XR 3,189,9476 1965 Pettkoske 18-36 3,192,561 7/1965 Archer et al. 18-5 3,257,7096/1966 Fernan et al. 18-36 XR WILLIAM J. STEPHENSON, Primary Examiner.J. HOWARD FLINT, JR., Examiner.

1. APPARATUS FOR FORMING A PRODUCT PRESSED FROM POWDER COMPRISING INCOMBINATION MEANS DEFINING A HORIZONTALLY ORIENTED BORE INCLUDING APOWDER CHAMBER, A PRESSING DIE PROVIDED WITH A CAVITY ADJACENT TO ANDALIGNED WITH SAID BORE, A DISPENSING MECHANISM FOR SUPPLYING POWDER TOSAID CHAMBER, A FIRST POWDER PRESSING MEMBER DISPOSED IN SAID BORE ONONE SIDE OF SAID CHAMBER, A SECOND POWDER PRESSING MEMBER, MEANS FORAPPLYING PRESSURE TO SAID SECOND PRESSING MEMBER, MEANS FOR RETAININGSAID SECOND PRESSING MEMBER STATIONARY IN ONE END OF SAID DIE CAVITYWHILE UNDER PRESSURE, MEANS FOR ADVANCING SAID FIRST PRESSING MEMBERTHROUGH SAID CHAMBER TO PRESS POWDER IN SAID CAVITY AGAINST SAIDSTATIONARY SECOND MEMBER, MEANS FOR RELEASING SAID SECOND MEMBERRETAINING MEANS UPON COMPLETION OF PRESSING BY SAID FIRST PRESSINGMEMBER, SAID SECOND MEMBER UPON RELEASE OF SAID RETAINING MEANSADVANCING IN RESPONSE TO